|CULBREATH, A - University Of Georgia|
|SELPH, A - University Of Georgia|
|WILLIAMS, B - University Of Georgia|
|KEMERAIT, R - University Of Georgia|
|SRINIVASAN, R - University Of Georgia|
|ABNEY, M - University Of Georgia|
|TILLMAN, B - University Of Florida|
|Holbrook, Carl - Corley|
|BRANCH, W - University Of Georgia|
Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2016
Publication Date: 3/1/2016
Citation: Culbreath, A.K., Selph, A.C., Williams, B.W., Kemerait, R.C., Srinivasan, R., Abney, M.R., Tillman, B.L., Holbrook Jr, C.C., Branch, W.D. 2016. Effects of new field resistant cultivars and in-furrow applications of phorate insecticide on tomato spotted wilt of peanut. Crop Protection. 81:70-75.
Interpretive Summary: Tomato spotted wilt virus (TSWV) can cause devastating yield losses in peanut. Management of TSWV is dependent upon integration of several factors that suppress epidemics of the disease. The use of cultivars with field resistance is the single most important practice for management of TSWV. TSWV is transmitted by thrips, and the insecticide, phorate, has been observed to suppress TSWV in peanut. Responses of several new cultivars to phorate have not been characterized. Therefore, the objective of this study was to determine the effects of in-furrow application of phorate insecticide on epidemics of TSWV and on yield in new peanut cultivars. Several of the newer cultivars had final incidence of TSWV that were less than the moderately resistant check cultivar. With higher levels of field resistance in these newer cultivars, benefits from use of phorate insecticide for TSWV suppression were small, and typically did not result in yield increase. Based on these results, several of these cultivars should allow greater flexibility for insecticide choice for thrips management without increasing the risk of losses to TSWV. Farmers will be able to save costs and increase profitability by using with these highly resistant cultivars.
Technical Abstract: Field experiments were conducted at Tifton, Georgia from 2008 to 2014 to determine the effects of new peanut (Arachis hypogaea L.) cultivars and in-furrow applications of phorate insecticide on severity of tomato spotted wilt (TSW) caused by Tomato spotted wilt virus. Several cultivars, including Florida-07, Georgia-06G, Georgia-07W, Georgia Greener, and Tifguard, had final incidence of TSW that were less than that of Georgia Green. In-furrow applications of phorate insecticide reduced incidence of TSW in Georgia Green in three experiments in which that cultivar was included. In-furrow application of phorate insecticide reduced incidence of TSW in most cases where incidence in nontreated plots was 10% or higher. Cultivars Georganic, and Georgia-10T, had final incidence of TSW that was lower than that of Georgia-06G, or Florida-07 within nontreated plots across 2011-2012. Georgia-10T and Georgia-12Y had final incidence that was lower than that of Georgia-06G, Georgia-07W, Georgia-09B and Georgia Greener across insecticide treatments in 2013. In-furrow application of phorate increased yields across cultivars in 2008-2009, and increased yield of Georgia-09B in 2010. In most cases, phorate had no significant effect on yield. With higher levels of field resistance in most of these cultivars, especially those such as Georgia-12Y, benefits from use of phorate insecticide for TSW suppression were small, and typically did not result in yield increase. Based on these results, several of these cultivars should allow greater flexibility for insecticide choice for thrips management without increasing the risk of losses to TSW.